1. Field of the Invention
The present invention relates to wireless communications, and more particularly, to a method for monitoring a downlink control channel in a wireless communication system, and a wireless device using the method.
2. Related Art
Long term evolution (LTE) based on 3rd generation partnership project (3GPP) technical specification (TS) release 8 is a promising next-generation mobile communication standard. Recently, LTE-advanced (LTE-A) based on 3GPP TS release 10 supporting multiple carriers is under standardization.
As disclosed in 3GPP TS 36.211 V10.2.0 (2011-06) “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation (Release 10)”, a physical channel of 3GPP LTE/LTE-A can be classified into a downlink channel, i.e., a physical downlink shared channel (PDSCH) and a physical downlink control channel (PDCCH), and an uplink channel, i.e., a physical uplink shared channel (PUSCH) and a physical uplink control channel (PUCCH).
To cope with increasing data traffic, various techniques are introduced to increase transmission capacity of a mobile communication system. For example, a multiple input multiple output (MIMO) technique using multiple antennas, a carrier aggregation technique supporting multiple cells, etc., are introduced.
A control channel designed in 3GPP LTE/LTE-A carries a variety of control information. The introduction of the new technique requires to increase capacity of the control channel and to improve scheduling flexibility.